2.15. Isobologram analysis

HepG2 cells seeded in a 96-well plate were pre-treated with multiple doses of TCASK10 (Tocris) or Rosiglitazone (Sigma) or their combination following which MG132 (10 μM) was administered. After 16h, cell death was detected by LIVE/DEAD®Viability/Cytotoxicity Kit (Invitrogen) and fluorescence was measured with BioTek Synergy H1 Hybrid Reader (Vermont, USA). Multiple drug-effect analysis of Chou-Talalay based on the median-effect principle was used [26] and the combination index for synergism or antagonism or additive effect was calculated as described by Chou [27].